Practicality of wood gas electricity.

[Bigbo1234]

I have recently become very fascinated with the idea of wood gas as a fuel. I saw the Mother Earth news article about the truck and got my gears turning. Would it be practice or possible to build a stationary gasifier in a small out building to power a generator to produce a homesteads electrical needs? I believe I have ample wood to satisfy the project but don't know if its feasible? Any thoughts?

[beenthere]

Have you read the thread(s) that our members have posted about their wood fuel rigs?

[grweldon]

I have also lately been bitten by the wood gas bug and I also am interested in generating electricity.  I have a couple of concerns about producing gas that is "clean" enough to allow an engine to run four a few thousand hours before failing due to stuck valves, but I'm definately going to try it.  I have a welder in the budget for spring.  I don't yet have a generator, but I do have several lawnmower engines around that have corroded carburetors due to ethanol-blended gasoline so they would be perfect to test with.  A simple automobile alternator could yield interesting results.  Like I say, I'm definitely going to try it!

[Ianab]

I'd think you would want to tie it in with a full "off grid" system. Reason being that you will have a varying load and generally need at least some power 24/7, even if it's only to keep clocks running. Setting a wood gas generator that can go from 100w to 3,000w at the flick of a switch would be tricky. But if you had it "putt putting" producing 1,000w for part of the day, and keeping a battery topped up. Then power the house off that via an inverter. You could have a solar panel, windmill, micro-hydro tied into the system, and just run the wood engine as needed.

Recovering heat from the engine to provide hot water would improve the efficiency as well.

Ian

[Leigh Family Farm]

Also, look into the viability of keeping the fuel supply topped up and having enough fuel supply handy. The little research I did showed that small systems (down draft) work because the top is sealed which forces the air to be drawn downwards. Thus you have to seal the top after each time you load fuel. The GEK system can only handle 8 hours of fuel before you need to refill. I think thats a 55-gallon drum of wood chips every 8 hours, which in my book equates to a lot of wood chips in a month. Very small systems could be used to run a generator to charge batteries for a few hours. Check YouTube for sample videos. Larger systems are eve more complex and require a full-time operator.

Look at the GEK Gasifier. Its open source design. There are many free articles & publications on gasification.

If you were looking to power a homestead or small cabin part of the time, then a gasifier would work. I would personally combine it with a solar & wind set up just so I could have power 95% of the time with out much effort.

[Al_Smith]

Mother Earth news way beck in the early  to mid 70's had an article about using a wood gassifier using an OHV Pontiac Tempest engine .It worked but being mother earth  they captured the heat from the radiator,used a heat exchanger to capture heat from the exhaust and just went bonkers over it. Which I might add was typical of the ways they did things .They eventually cooked the engine .

By now maybe someone has figured a way to purify the producer wood gas so it doesn't eat the engines up .Nice idea maybe if you didn't have to replace the engine every 6 weeks .

[Paul_H]

You don't purify the gas,you build a proper gasifier,run it properly and the tars are cracked in the reduction zone.I've driven about 1500 miles on wood so far with no ill effects on the engine and there are a whole lot of others that have driven much more.
Of course,you being a self decribed barroom barrister,you are simply trying to liven the discussion regardless of facts or evidence  ;)

[Al_Smith]

You're reading something into what I said .I was refering to the experiment Mother Earth News did during the early to mid 70's and suggested somebody since might have found a way to purify the gasses .You evidently have from what you say ,case closed . ;)

[DanG]

The very title of this thread is pretty close to being an oxymoron, I'm afraid.  That being said, it sounds like a great experiment, hobby, and learning experience. 8)  I have thought about doing it myself, but it is just another of the many things I'll never "get around to." : :D  In order to make it feasible as anything beyond a novelty, you would need to reap as many benefits from the operation as possible.  The things I have thought of are to use the excess heat for, well, heat. You could warm your house, a greenhouse, or kiln with it.  Then you could package and sell the charcoal by-product to complete the hat trick if you used an appropriate wood to produce the gas.

[fuzzybear]

GEK out of California has a "freeware" program building gasifiers for all sorts of engines. It is a group of people all over the world building and testing these units, and they share their improvements and disasters with every one via the web. They have turned mainly twards producing power with these units, running gen sets of all sizes.  The blue prints are free on the web and they have an excellent staff that is not afraid to try something new or help with PROVEN systems.
  I had a gentleman here from Arizona with a unit running a 1977 Ford 150.  He was on his way to Deadhorse Alaska, from Pheonix. He said he has not a lick of problems, and never had a problem finding fuel wood. The top speed for his truck pulling a vintage pop up trailer was 70mph.  impressive to me.
  There is an old IH 5T truck in the bush here that used to haul wood to town burning wood as fuel.  It was based on the Sweedish model of WWII.
   I have been slowly collecting the parts I need to run the skid truck on wood. The problem I had was figuring out the correct size for my engine. I didn't think it could be done because of the horsepower my engine makes  (400hp).  When I reached them they said "No Problem", it seems that some one in Florida has built a drag racing car with a 400hp+ engine running wood gas. It is supposed to be turning 6500rpm and runs the 1/4 mile in 13.1 sec.  FAST for a wood burning street legal car.
   They have unit for sale prebuilt to you needs, but are very helpful to those that do it themselves. Check them out at gekgasifier.com
FB

[Al_Smith]

The use of "producer" gas probabley goes back centuries .

For one it was widely used in the large steel mills that once were the worlds leading output of steel in this country which have been allowed to die on the vine but that's another subject .

Early on perhaps 1880ish they figured a way to capture the waste gasses from coke ovens etc and use this otherwise waste gasses as a fuel .Around that time or later up to mid 1920 they used these gasses for the generation of electricity using huge horizontal cylinder engines some designed by Allis Chalmers .Fact Carnegie steel had a bank of engines rated at over 30,000 HP installed in 1906 I think.

During WW2 countries in Europe because of neccessity used some form of producer gas to power busses etc because of a shortage of gasoline which worked well considering.

Recently there have been groups who have had an interest in this .Now practicality and feasiblity  are not one in the same .Feasibility has been proven ,practicality would be determined by the end user . 

[r.man]

A friend of mine has been building a gasification unit in his spare time for about two years. Taught himself to weld and is on his third prototype I think. He switched from wood fuel to homemade charcoal after finding the single process units to be too tricky. His idea is to produce charcoal in one process and use the waste heat to heat his greenhouse and then use the charcoal in a simpler gasification unit to provide fuel for a generator. Sounds reasonable.

[Jim Timber]

I'm curious why you wouldn't just make a steam engine to run the generator?

[grweldon]

I'm curious why you wouldn't just make a steam engine to run the generator?

I'm struggling with this question as well.  The biggest negative to steam would be the need for a boiler... a pressure vessel with the potential to fail catastrophically, especially when constructed by someone who doesn't have a ton of experience welding.  That's part of the intrique and attractiveness of wood gas.  It's scalable and can be constructed by a do-it-yourself-er.  Plus, internal combustion engines are extremely common in ratings from 3 to 300 horsepower.  Steam engines not so much plus they are extremely expensive.  I have the ability to construct a steam engine as I work in a manufacturing facility and have machine tools available, but most don't.

It DOES seem to me that steam would be more reliable over the long term, but again, you can build several gasifiers and buy several 10-20 HP engines for what a decent boiler and steam engine would cost if you had to buy them outright...

Still... I'm not sure that wood gas is the way to go compared to steam.  It may be and I'm sure I'll try it, but I'm not sure it is the answer...

[Jim Timber]

Very valid points. 

Just seems like if they used to power cars with them, it would be an easier solution with less fuss.

I'm curious to build a steam engine myself, and plan to do it one day.  I have all the machinery needed in my personal shop. I just have more pressing projects in line.

[mad murdock]

Monotube boilers can be made cheaper and more efficient (operationally) than fire tube boilers, and plenty of safety features can be built in to prevent boiler failure.

[grweldon]

And then you STILL have the issue of the engine... can't stop in your local big box store and buy one, but if you could it would be terribly expensive...

[Al_Smith]

I think what you all need to remember is this wood gasification to use as automoble fuel is more of an experimentation in this day and age than anything .

During the days of the big steel mills using recycled waste gas it was just a viable option to large steam engines which they already had .

During WW2 in Europe it was a neccessity because they didn't have any gasoline .

Now regardless if it works or not which it certainly does I for the life of me just cannot see many people using it .Just how many people are going to roust out of bed an hour early to build a fire to get a head of wood gas going just to drive to work ?It ainta gonna happen .

Same deal with a steam engine .Why it would take a full time steam engineer and a woodsman just to keep enough wood to keep it fired for any length of time .I can just see these guys having their wives tend the boiler all day long while they are at work .That would be about as popular as turd in a punch bowl to put it mildly . :D

[Jim Timber]

Yet tens of thousands of folks heat with wood boilers year round.  They load them once or twice a day.   Granted they're not running a generator (much higher energy demands), but it's not to say it can't be done.

So here's the argument - if you have to buy and transport gasoline from some reasonable distance, or cut and transport far less wood locally: a steam engine could in fact be more efficient.

The maintenance issue is another straw man argument.  You're talking about fueling an engine with a gas that has the potential to glue the valves shut.  You can't assume that you'll always have the tar cracked before it reaches the engine.  I'll take a stab in the dark here and say you have never rebuilt the heads on a car before when you say this is just a maintenance issue.  1500 miles on a car?  Really?  That's not even one oil change.  How many hours on the engine with that mileage?  If you were using it to power a dwelling, that might get you a week, maybe, probably not; as it's likely under 50 hours run time.

We're not talking about transportation here, we're talking about electrical production.  If all you want is enough to power some lights and a laptop - get a solar panel and some batteries.  It's a far more demanding task to make enough juice to run equipment and appliances.  I don't want to limit my choices to using the blender or having lights, so maybe I'm approaching this differently than some of you.  ;)

[Paul_H]

Welcome Jim.

You are a machinist living in a free country and nobody here will stop you from building a steam system.The only person stopping you right now is you. You won't hear any arguement from me,I would enjoy watching your progress from planning to completion.
What stage are you at right now?

[Jim Timber]

I'm at "knee deep in other work and not even sourcing parts or materials."   :D

Living off the grid is a novel idea.  I'm more concerned with how to raise the 12K I need to bring power in for my home and shop in the middle of the 80 acres than how to bypass needing the PowCo.

I also have a 18KW 3ph generator head which may one day be turned by a steam engine, but that's not the reason I have it.

[Paul_H]

I hear you,we all tend to have too many irons in the fire.

The maintenance issue is another straw man argument.  You're talking about fueling an engine with a gas that has the potential to glue the valves shut.  You can't assume that you'll always have the tar cracked before it reaches the engine.  I'll take a stab in the dark here and say you have never rebuilt the heads on a car before when you say this is just a maintenance issue.  1500 miles on a car?  Really?  That's not even one oil change.  How many hours on the engine with that mileage?  If you were using it to power a dwelling, that might get you a week, maybe, probably not; as it's likely under 50 hours run time.

If you are addressing me,I would say it is a full blown case of assuming making a...,well you know the rest.I enjoy the tinkering aspect of woodgas as a hobby and have no illusions about it being a replacement for liquid fuels.Your stab in the dark about rebuilding engines was as misguided for certain.
Personally,if I wanted to be off grid(i don't) then a search for land with a good water source for power generation and irrigation would be the top of my list.We heat almost exclusively with wood for 6 months a year but by the time Spring arrives I can't wait to abandon the daily chore of feeding the woodstove.

[Ianab]

Steam engines are not exactly modern technology  ;) :D

They were patented in 1781, so that's the level of technology you would need to actually make one.

In the "something you could knock up in the shed on a rainy weekend" category is this.
http://www.youtube.com/watch?v=dTuNgXpjy0I

OK it could do with a bit of development and refinement, and efficiency is probably not great, but it's making electricity out of wood. All constructed of basically scrap metal.

Ian

[Jim Timber]

Thanks for the welcome.

Paul,
It was a general statement from my observations across numerous forums over the past few years, not directed at anyone here specifically, but at the generalizations people employ in their reasoning when trying to argue for the process.

Last week I stumbled across a perpetual energy generator where some guy spins up a motor, then unplugs it, then turns on a grinder and a drill press to show that it's making juice.  :  What he failed to do was show that when a load was applied to either tool, it no longer functioned.

Where I was going with the engine rebuild comment is that the perception of economy through readily available parts is a fallacy in itself.  That you can source an engine cheaply, doesn't make using that engine more economical over the long run.  Durability with the given fuel source hasn't been proven to be 100% reliable, so you can't argue a best case scenario when that's certainly not the average outcome.

[mad murdock]

For power production (electricity), I think water is the best, if available, wind and solar are not steady enough, for total dependency on their own, and if one is looking at practical off grid living, some combination of power generation is required, for dependability and redundancy, so if a portion of your point source "grid" requires a temporary shutdown and maintenance, you don't have to go without power for any length of time. I think "point of use" power is a good idea. Using things such as LED lighting and Joule Ringers to maximize power for certain applications can really ago far to provide a little energy "independence". If one is going to need serious power even intermittently in the course of day to day living, major storage capacity, or increase generation capacity even if only 10-12 hrs a day is a necessity to have real off grid power, IMO. Steam is a reliable and feasible source to look at, in my view, engines may cost more than an internal combustion, but they will outlast many a liquid internal fuel burner, unless you can feed one natural gas or LPG. Everything has its place. There are even opportunities to utilize local methane production if you have animal waste or other organic materials at your disposal. Knowing how to use what you have around you is key, there are lots of alternative resources around, unless you live in one of the many concrete "deserts" scattered around.

[grweldon]

Guys,

First off, from what I've read (I have zero personal experience) the gas from a gasifier can be filtered through wood chips and sawdust to remove a great deal of the tar.  As has been mentioned, a properly designed gasifier would generate gas that would contain a relatively small amount of tar and not be considered a "tar generating machine".  When I build my gasifier, I have several old engines around that I will test to determine longevity and mode of failure with the intent of improvement of the gas quality.  I believe the issue of "dirty gas" can be addressed to the point that it is a non-issue.

I don't necessesarily intend to have a mobile gas generator, but it's nice to believe that I could if I needed to.  My intended use of wood gas would be to reduce my reliance on the need for power from an external source, nothing more.  I'm not investigating wood gas as a method to save money on power, rather, how to survive relatively comfortably if/when the day should come that power isn't available.  As for steam, not to mention the issues I brought up previously, again, it doesn't seem to be practical for my purposes because  I rely on municipal water.  It's quite expensive.  Even then, if power is not available, my only water source for the moment won't be available either as pumps are required to get the water from the ground to the towers for pressure.  I could collect rainwater, but my use for that will be more important, I will treat it to make it potable (again, reliance on raw materials for treatement).

As Mad Murdock mentions, a wood gasifier would work best in a multi-generator approach using other methods of power generation in combination.  Personally, the way I would use a gasifier would be to charge (or assist in charging) a bank of batteries and using an inverter powered by those batteries to produce AC.  That would mostly overcome the on/off issues with firing and fueling a gasifier.  Batteries are still a maintenance item and force you to be dependent unless you know how to make your own.  Myself, I'm not a chemist or have any background in chemistry.  I don't know how to make hydrochloric acid and if I did, I'm sure I would have to buy raw materials... again, more dependence.

My desire is to have the ability to be self-reliant, either for a specified period of time or indefinately.  I have acres of readily available wood.  My sawmill is driven by an internal combustion engine.  My tractor is driven by an internal combustion engine.  If push comes to shove, I'll have to run them on something.  It's not practical for me to amass hundreds of gallons of liquid fuel (removing the conventional generator from my list of options as well).  Of course I'll have to have some amount of fuel on-hand for chainsaws until they break and require parts (cudos to y'all who have large chainsaw collections).

I don't consider myself a prepper, but I DO think the day will come in my lifetime (only have a couple, possibly a few decades left) where the modern conveniences we have all come to rely and depend on will disappear.

Just my take and my reasoning for exploring "producer gas".  If I were looking for a way to reduce my energy cost and assume that everything including infrastructure and economy would not change, I'd go with a grid-tied solar system since I live in Alabama and we have plenty of sun.  Obviously I'm looking at a different scenario.

[Paul_H]

It was a general statement from my observations across numerous forums over the past few years, not directed at anyone here specifically, but at the generalizations people employ in their reasoning when trying to argue for the process.

Reading and studying is one thing but building and operating is another entirely.There was a fellow named Mark on a woodgas forum I look into occasionally and he joined up and right away began to argue for steam and even against folks like Wayne Keith who has driven across the country coast to coast a couple of times.
What struck me was this fellow had zero practical experience with either technology and yet he argued for one and against the other.He had no intention to build a steam system but was strongly urging members of the group to build.

I think of him as a Tom Sawyer,a fellow with no ambition to paint the fence himself but wanting others to do it for them.

[Jim Timber]

Just finished a logging arch, and will be starting on my own bandsaw mill as funds allow.

Here's a little thread on the log arch:  http://www.qdma.com/forums/showthread.php?t=60228

Dealt with wood gasification briefly in HS 20+ years ago (special project for industrial tech class).  Was a helicopter tech in the army (jet engines), and have spent numerous years in automotive and medium duty truck repair.  I've also gotten a naturally aspirated wankel rotary 1.3L up to the same HP levels as it's turbo incarnation with 30lb/ft more torque and still able to idle down to 399rpm (at which point the ECU no longer thought the engine was running and would kill the spark).  But that's not really an achievement at 160HP per litre using nothing but a die grinder.   :

I may have just signed up here, but I wasn't born yesterday.   

The other option rather than gasifying the wood would be to make alcohol out of it.  Stills are pretty easy and nearly fool proof.  Carb adjustment just needs to be about twice the jet size, and be sure to change out all the gaskets from cork.

[Paul_H]

So if I read all about helicopters and spoke of them with authority you would be duly impressed? 

I read and studied about sawmilling for a few years before purchasing and operating and found that nothing beats practical experiences and that my view of milling production before hand wasn't reality.
I know a member here personally that is a steam engineer and has many more impressive achievments but he is too humble a man to list them.

[Jim Timber]

I suppose I should've mentioned my stretch in the molecular effusion cell fabrication industry too. You might know what that is, since it's a higher form of what the gasifiers do.

I'm not here to toot my horn.  You called me out as a book worm with no practical experience, and I just told you why it's not true.

[Paul_H]

Impressive credentials if authenticated for sure but I don't believe I called you out on being a bookworm only but more of an armchair quarterback on woodgas and steam.
To generate the power(by steam) you want for your home one day,what volume of water and wood do you expect to use?

[Jim Timber]

Why would I calculate the energy needs of a building which not only doesn't exist yet, but hasn't even been designed?

Driving cross country numerous times on alternate fuels is fine and dandy as well, but the hours of run time are miniscule in comparison to a 100% duty cycle application like running a building.  Engines which do well in those applications are not four stroke gasoline either, they're diesel.

[Paul_H]

Driving cross country numerous times on alternate fuels is fine and dandy as well, but the hours of run time are miniscule in comparison to a 100% duty cycle application like running a building. 

Yes,but he is thousands of mile ahead of you in knowledge and experience with woodgas so when he speaks,I tend to listen.

You read right about the diesel engines being a better choice because woodgas likes a high compression engine.

[grweldon]

Paul, Jim,

How about let's cool it on the teat-for-tat stuff? While y'all haven't yet ceased being civil, seems as if there is potential to get there.  I would rather (maybe others would too?) talk about the subject at hand rather than debate credentials.  I see that both of you are highly qualified to comment.  Could we please remain productive?  I was enjoying the thread until it digressed...

BTW, that is a super-nice log arch Jim!

[Paul_H]

Thanks for your comments but I wish you would allow me to do what I am doing.I am not hot under the collar and haven't used my credentials although I did mention two others who I respect.

Thanks for your concern but I will continue as I see fit.

[Jeff]

I'll not be making any welcoming statements.  But I do have a few comments. First, grweldon, please don't try and moderate my fellow admins. I don't like it.


Jim Timber. I was called in to read this topic over to form an opinion on why it is heading in the direction it headed. I've determined it went south because of possibly two reasons. Both related to you. It is either your writing style, or your attitude.  Either one or both need to be adjusted to be a member here. If you would like to continue without the air of superiority, then fine.  I will always always always side with my admins on an issue, but in this case, I'm not siding with an admin. I'm siding with someone that has been there, done that, documented it for all to see against someone that thinks he knows something because he thinks he says he knows something else, comes in swaggering on a forum that 99.9% of the time is civil no matter what the discussion and causes this sort of disruption.  I don't know where you came from, or what was deemed appropriate conduct there, but here, this ain't going to fly.

[Al_Smith]

  Wow and I didn't even liven up the conversation .

Anyhoo some comments .Producer gas,char gas ,coal gas or whatever you call it was in use before wide spread distribution of natural gas .The later did not come into effect until the 30's .The first use of syn gas was around 1901 to power an automobile.

If you do a Google on the subject there is some interesting methods and pictures  such as transporting the gas in what actually is a large balloon type envelope on top of an automobile .--more --

[Al_Smith]

Now this boiler business .Firstly a wood "boiler" ,OWB is a water heater not a producer of pressurized steam neccessary to power a form of usable rotational power .

So that said it takes 34.5 pounds of water heated to vaporization at atmospheric pressure to produce one boiler HP or approx 34,000 BTU per HP per hour .A boiler is around 80 percent efficient so it takes about 125 percent of that .One pound of 20 percent moisture content firewood produces about 8-9,000 btu of heat .Going from heat to mechanical would be around a 90 percent
"coupling coefficient " and likewise going from mechanical to electrical with a generator would be another 10 percent lose .

You do the math on say 15 HP of steam to run around 10-12 KVA of power and look at the amount of wood it would take .

What I'm trying to point out is as they say nothing is free .You might like to be free of the power company but small scale production of electrical power you'll never beat them at their own game .

Never the less small scale production of electrical power is an interesting subject and worthy of a discussion .

[WmFritz]

   I'm sure some of you guys have heard of Ben Peterson.  I did a quick search here and came up empty. The company he started, called Victory Gasworks,  sells components for gassifiers or complete turn-key systems.  A look at the spec sheet shows it takes 2.5 pounds of biomass for 1 kWh of electricity. It also supplies hot water.  I think he has a very nice system but, pricey.


http://victorygasifier.com/

[WoodenHead]

I live off grid using solar primarily, but also wind.  I have a backup diesel generator.  I looked at the GEK gasifier, a few others, and steam options.  Unless you scrounge and manage to piece together a very cheap system, the cost of the equipment is as much or more than I could buy solar panels and racking for.  I will need to replace or overhaul my diesel generator someday, so I am still toying with the idea of a gasifier.  But my best option may be to simply add more solar panels.

[just_sawing]

One of the ideas that I am currently working on is the fact the wood gas is compressible. This give me an avenue to produce now use later.
Here in the south it would be good to just run a generator for a few hours in the summer switching the AC on full blast and cooling down the house cool. When the unit runs out of fuel you switch back to the normal electricity. I burn slabs to get rid of them and I would live to make gas and use less electricity.
I am a firm believer in many sources with many opportunities. The gassifier isn't the end all but one of the bricks in my house that the wolf can't blow down.

[Ianab]

Yes, it could be compressed, like Natural gas, but the cost of the high pressure compressor needed to fit a useful amount into a cylinder is a major factor for a small system. Same issue with producing methane from Cow manure and storing that. Yes it's possible, but the cost makes it a bit impractical.

Ian

[Paul_H]

Just_sawing,

Below is a quote from the FAQ's at Woodgas.net

http://www.woodgas.net/faq.html

#1) Why don't you make the woodgas at home and then compress it in a tank and drive on the tank of compressed woodgas.

A) Well their are actually four reasons.

1) Woodgas is a extremely low BTU fuel it only has 150btu's per cubic foot, making it very bulky and even if you compressed it to 3600psi you would not get any driving range out of the tanks as woodgas is used in a 1:1 fuel air mixture. The range of a 100 gallon tank compressed to 3600psi would be less than two miles.

2) When you compress woodgas to extremely high pressures you are forcing the mixed gas content closer together and the free hydrogen will steal the O off of the CO sooting out the carbon and forming water. It is also speculated that the same thing slowly happens with CO under high compression. The CO will soot out a C to make CO2.

My advice would be to run your woodgasifier for a year or so and experiment a bit with gas storage and see where that leads you.I was talking about this very thing yesterday with a customer of ours at the shop.He has been very interested in our woodgas truck and has a few ideas on how it can be improved and yet he has declined a few invitations to be involved in the lighting of and driving of the truck.
I know when I was building the system there was nobody near enough for me to go visit and see a operating gasifier but if there had been an invitation from anybody within 500 miles I would have been there. Mike Larosa from WI told me to build and test first and then try new ways and he was right.
My hope is for your success and also that you would share your successes and failures freely with others that we might have progress,

[pineywoods]

Wood gas could be used to make gasoline, ethanol, and diesel fuel. Just isn't practical to do so in small batches. I did a bit of research on this a while back. You need high pressure )4000-5000 psi and heat (450 + deg centigrade). a catalyst (iron oxide) is ineeded also. The technology is nothing new, developed by the germans in ww2 to make diesel fuel from coal. The process is quite energy intensive, and prone to runaway reactions. .

[Old Wood Whacker]

You can store wood gas and compress it with a natural gas compressor. I've been talking to someone who is doing it. The compressor costs $3500 according to him. He's been grid free and makes all his fuel for his equipment and vehicles for 12 years now. I'm planning on going out to visit with him this winter. I will report on what I find when I return. It looks very promising at this point. It would be cost prohibitive for a single homestead or small mill, but he says that the way to do it is to form a local co-op and have multiple families invest in the equipment, as even a small gasifier can supply the needs of up to a half dozen homestead or small farming operations. I'm intrigued.

Stability comes from a stable fiber source. Kiln dried wood, perhaps pellets, might be beneficial. A small pellet mill isn't that expensive--about $2K. That makes the fuel cleaner and consistent, which is often the problem with wood gas. He claims that doing it this way that it is very efficient, clean and does no more harm to a gas engine than propane or nat gas. He has diesels he converted as well, but he says they still need to run on 20% diesel.

[maple flats]

Yes, it could be compressed, like Natural gas, but the cost of the high pressure compressor needed to fit a useful amount into a cylinder is a major factor for a small system. Same issue with producing methane from Cow manure and storing that. Yes it's possible, but the cost makes it a bit impractical.

Ian

Wow, if it's impractical, I'll have to inform the progressive farmers around here that they should quit their methane fiasco!
Impractical becomes good use of resources with education.
As for wood gas, I have saved a few sets of different plans for making a woodgas generator. May not use it until our current sources fail but I will keep the plans for "when needed". The concept intrigues me.

[beenthere]

progressive farmers around here that they should quit their methane fiasco!

If not for the Fed money funding them, it prolly wouldn't happen or continue. Good to research the concepts and find out just what works and what doesn't tho.

[Thehardway]

Have been watching this thread for a while now and I guess a few things have been eating at me.  IMHO there are a few flawed assumptions here that need to be addressed and dealt with when dealing with electrical production and off-grid use. 

First we must recognize the difference between base-load and peak loading.  If I were to design an electircal production system using either wood gasification and IC engine or a wood fired steam engine, niether of them would be running a large engine or producing power at peak demand levels.  It would be a waste of energy and resources and would make my operation inefficient, and cost prohibitive.  Very few if any of us use 18kW of power 24/7 and if we did, we should certainly look to reduce our consumption and increase the efficiency of our home/shop.

The way to do the wood gasifier power project would be to take a small, simple, but fuel efficient engine that tolerates impure fuels, is easy to repair, (few working parts) and was made to run all day long.  Something like a small 1930's era JD tractor engine.  This would be coupled to a smallish generator unit that it could drive easily while merely running at idle or low rpm.  Something on the order of a 1.5-2KW genny.  1.5-2KW plant will run anything you can plug into a 110V , 20A circuit.  This makes it a practical size.  you can use handheld power tools, microwave oven, single burner stove, small shallow well pump, etc.  You would then build some kind of storage bank for the excess power produced that was not being consumed immediately.  It could be fed back into the grid, used to charge batteries, used to pump water into an elevated reservoir to later produce power using hydro, or any other form of energy storage you could conceive.  In conjunction with this, all available energy should be taken from the process such as exhaust heat reclamation being used to heat hot water for domestic use, pre-heat for a steam production system, etc.  With low cost energy readily available in this country we have become spoiled and do not make good use of CHP potential.

The same applies for a steam driven plant.  In the world of utility scale electrical generation, the steam based power plants are optimised and operated to run at 100% capacity for base load. (Understood these are turbine engines and not piston based) Peak loading is accomplished by bringing on line small scale units in succession as demand ramps up.  Steam is not good for this.  Demand power is preferably hydro power but nowadays is more often natural gas fired reciprocating engines or turbines that spin up quickly and can quickly assume load while easily meeting emissions requirements.

Old diesel engines can in some cases be converted to run on natural gas or on a natural gas liqui fuel mix and I believe they are prime candidates for wood gas as well with some tweaking.

The idea of running these systems in a bug out scenario are purely hypothetical and I doubt it would be very successful. Without getting political,  I think whole scenario has been glorified by Hollywood and the internet and poorly thought through.  The availability of firearms is much greater than in previous times and looting and pillaging will likely limit the success of peacefully producing electrical power and living in a home unmolested, regardless of your location or power source. Unless you are heavily fortified or booby trapped your time of productivity will be short.

If you want to fool with it for fun and knowledge, it is a great hobby, otherwise, if you really anticipate and are wanting to prepare for apocalypse or total government collapse, you might be better off spending your time learning Arabic, Chinese or Russian... at least then you could beg for your life while they destroy your home and confiscate your mill and power plant?

I think for stationary power production, a low pressure steam engine/generator with heat recovery would make much more efficient use of the wood, especially if burned in a rocket stove type setup than by using a gasifier to just run an IC engine and generator.  On the other hand, mobility is much better accomplished using an IC engine and gasification than steam, primarily due to the weight of the water that must be transported for a steam based power plant.

I would like to play with a steam based system and just run it for a few hours a day doing net metering through grid tie.  I think I could produce enough in a few hours of continuous run to zero out my bill and I wouldn't have to tend it all day.  I could use thermal mass as a storage medium to provide Domestic hot water for the remainder of the day until next burn cycle which right now is my primary use of electrical energy. 

[Leigh Family Farm]

Northman,
You bring up an interesting point in the last paragraph about running your system for a few hours at full load to offset your current power comsumption. I think this way would be a great way for someone to zero out their electric bill. I wonder how long you would have to run at full load to accomplish this? Daily? Weekly? I'm just imagining running the system for a solid 8 hours one day a week (say from 4pm - 12am on a Friday) when I am least busy. This is just me and my situational thinking so take it for a grain of salt on the rim of a margarita glass  ;)

[marsofold]

I have considered other ways to generate electricity from wood. Looked at running a muffled pulse jet engine (no moving parts!) from wood gas. The pulsejet would have to be long, like 16 feet or more due to the low combustion velocity of carbon monoxide, and a wind turbine placed in the incoming engine wind stream to generate electricity. Or a fluidyne stirling pump engine running a small common hydro-turbine system for battery charging. There are posts on youtube with thermoacoustic and metronome stirling engines with the piston/rod being the only moving part cranking a small generator. In 1843 one of the most powerful known methods of generating electricity was an Armstrong steam generator that made high voltage power with no moving parts, an invention that got Armstrong admitted to the England's Royal Society. Such ultra-simple gadgets with little or nothing to break down appeal to me, even if not rather efficient. 

[maple flats]

ON an episode of Mountain Men on I believe the History Channel, Eustace Conway, one of the characters (and I do mean Character) made a gasifier to power his old pick-up truck. Look up Gasifiers, there is really lots of info.
In fact back in the 40's or 50's the US Ag Dept printed a booklet showing how to build one to power a farm tractor.

[Al_Smith]

Eustace comes up with all kinds of things out of the ordinary . I get amused watching his antics which usually work  .One of the best was using hydraulic pressure from a stream to run a small electrical generator using a water turbine and a small three phase motor .Years ago Mother Earth News had an article of a co-op in West Virginia doing the exact same thing using a larger motor, I think 75 HP .
These are not new ideas ,just revisted .For example at one time in the huge steel miles they used "producer gas " using giant horizontal cylinder low speed engines to turn giant generators to supply electrical power to run the mills .In those days the electrical utility companies did not  have a capabilities to do .Plus the producer gas was just a by product of burning coke in the blast furnaces that would have otherwise just have gone  up the smoke stacks any way . Free fuel in a way .

[peakbagger]

It takes a lot of elevation head and volume to generate enough power to drive a sawmill. The Eustace segments are edited heavily and its not beyond the show to take liberty with the facts to make a story. He along with the other folks on the show are paid actors and work off a script. Its likely that his income from the show would have easily paid the various debts he owes but that ruins the story. There are at least two water systems shown in the show over the years. His water line for the garden that he has to fix with the blue barrels is way to small to run a turbine unless he has a very high elevation head but the turbine that is shown in one show is not the type setup for high head. In another episode they have plugged line and its its much larger pipe, possibly 6" diameter.

With respect to wood gas engines the btu content of the mostly Carbon Monoxide gas being produced is quite low, yes it may power a truck but it will be way down on power. The wood has to be bone dry or the gas will be wet.

The steel mills still use producer gas but now they run it through gas turbines, producer gas is more volatile.  

[mike_belben]

i think you guys know that im willing to work pretty hard to make something from little if the long run works out.  every time ive looked at wood gas for even small industrial use it has come with too many complications.  the gas quality has to be very specific for long term use in a combustion engine without causing it harm or wrecking the oil with acids and stuff.   its fine for a lawnmower or some quick blast in your hemi to get youtube fame but i dont think the energy input to output ratio pencils out for reliable industrial application unless you are a big pocket sawmill willing to have the system engineered by pros who fly in and then you build whatever systems they say for consistent gas quality that may STILL be corrosive.  


i think wood fire into water into steam is vastly, vastly more sensible.  it built a lot of big nations, afterall. 

[Al_Smith]

That hydro turbine thing they use the same method to raise the pressure they once did for hydraulic mining in California .Start off with a big pipe and through a series of increasingly smaller pipes increase the velocity which in turn raises the pressure .
I forgot the specifics of that Mother Earth News article from decades ago but I believe the final pressure was 200 PSI in a 2 inch discharge .What I do remember about water pressure is it's 44 PSI per 100 foot head .To get enough elevation you might be able to do it in the mountains of North Carolina or Colorado but never in Ohio .
Regarding the Eustace series I'm certain being a so called reality TV it's highly scripted .Entertaining though I must admit .I wonder if he still has Wallace the old mule ?

[mike_belben]

Converging tube diameter will absolutely raise the velocity of fluid flow in a closed conduit but it will lower the pressure, thats bernoullie principle.. Pressure and velocity are inverse and ive messed with this a good bit in race engines, it is surprisingly true.


in a pelton water wheel generator like is commonly built, the higher velocity jet blasting the cups in an open or vented to atmospheric pressure enclosure, will apply more energy to the rotor because of the nozzle velocity increase. So youve got it right, and it does work.. just need some tweaking on the tiny detail.. Its inertia of water mass caused by velocity, impacting a cup and dissipating its stored energy into the rotor.

[peakbagger]

Ram pump technology was used a lot in hydraulic mining. Its pretty simple to build out of parts from Home Depot and work remarkably well. It takes a lot of flow with low elevation head and converts it to a higher pressure lower flow. The original cast iron versions could run for decades but most of them seem to end up in antique shops. 

[Al_Smith]

I've never lived anywhere with enough elevation to use the principles of hydraulic mining or Pelton under shot turbines I do however own a 3000 PSI pressure washer and it is a good excavator in some applications .Some times you have to think outside of the box you know..  

[Al_Smith]

This wood gas thing if it hasn't already been mentioned was used during WW2 in England to run busses etc ..I doubt they ran very well nor did the engines survive very long but they made do with what they had .
For that matter you can made a sort of crude oil from organic material under heat and pressure .Then run it through a vacuum distillation unit and get a crude form of gasoline .Of course in all that experimentation you could blow yourself, or parts of you into the next county if something goes awry .I don't think I'll delve into it myself . :D

[mike_belben]

its been a long time, but i think i remember concluding that the feed stock quality on wood gasification has to be huge and identical so that whatever ill come with it, could be adjusted for one time and managed.  so a mega mill with the same wood all the time can develop a program and eventually arrive at a stable fuel that doesnt wreck engines and engine lubricant from all the acids and CFCs or whatever junk is in the smoke.  this may require scrubbers and treatment conditioners and lots of labby sciency stuff.  more than i could tolerate.  expensive to do long term on an expensive engine without ruining it.  


so just tossing in any old willy wonka roadside junk (which is what alternative energy noobs always think.. ill just suck raw frenchfry oil from any barrel into my greasecar conversion) is not gonna last too long.  and that is the situation with waste veggie too.  refining the fuel is a long term process.  we get a lot of mega scale value out of our gas stations, even at $3 a gallon, compared to trying to make your own.  same for $60 a gallon maple syrup or $12 two by studs.  its outrageous, but try making your own some time!  there are major up front investments and labor inputs to get that first gallon, first stud, first mile. break even is pretty far into the future. 

[Paul_H]

Engines run well on wood or charcoal gas and the use of them during WWII saved thousands of lives and over a million woodgasifiers were built by companies such as Electrolux. Without fossil fuels for agriculture and transport starvation would have occurred on a massive scale.

The present day wood gasifiers are far better at producing clean gas than the Imbert style from WWII and they would make perfect sense today in an emergency situation. Presently there are many woodgas and charcoal vehicles built and driven in the US and worldwide. In remote flycamps where wood fuel is available  woodgas would make more sense than flying in barrels of fuel over long distances.

I like my gasoline but driving on woodgas is fun and handy to have if needed. I've driven a couple thousand woodgas miles on my 82 F150

Charcoal gasifiers that produce clean engine gas can be built in a day if the materials are on hand. We run a 12HP garden tractor with it and pulls quite well. Making a 1/3 of a barrel of charcoal takes little time to load but longer to grind and sort.

Here is a video showing the diversity of the wood gas vehicles from WWII

WW2 Woodgas History "We'll Meet Again" - YouTube

[mike_belben]

neat.  that makes you and puffergas for the only two ive encountered who have done it.  most are just talk and internet links. 

[Paul_H]

https://forestryforum.com/board/index.php?action=profile;u=8539  Member Ron has built a woodgas truck and a farm tractor and him and his family have hosted a few woodgas large gatherings.

https://forestryforum.com/board/index.php?topic=57556.msg906294#msg906294

[Al_Smith]

It's all related to what you want to do regarding a lot of alternatives ..You  could build a spring house instead of paying the power company for electrical power to run a refrigerator  if you wanted to ..I just would not want to walk a quarter mile  to the spring when my cold beer is in my garage 20 feet from where I'm sitting typing away with one finger .--Besides that I don't have a spring ----
Plus you could cut firewood with a bow saw ,I have one .I also have 40 or 50 chainsaws .I'll never wear out my bow saw .

[Paul_H]

Each to his own,I heard of one crazy begger that made a cylinder sleeve for chainsaw :D ;D

[Joe Hillmann]

I would say wood gas is only useful for making electric in fairly rare conditions.  I build a wood gas generator for a 5 hp engine.  It worked but cleaning the gas and the need for bone dry wood of the right size made it very difficult to use.  If the wood had a tiny bit too much moisture, or the gasafier was running too cool it would gum up the intake valve with tar and the engine would have to be taken apart after the run to clean it.

  I assume charcoal would solve that problem but then you have to make the charcoal.  If you can make charcoal and harvest the heat from making it to heat your home it would make it more worthwhile.

If you want power for a large number of hours the maintenance, and wear on the engine and gasafier will be high enough that you will soon decide you are better off using some other method to produce your electricity.  Solar is cheap.  Wind works in some locations.  Moving water has lots of power.  Battery storage is where things get expensive.  Reducing your power consumption and timing your power use at times of peak production will allow you to use a much smaller battery bank than what you need at first glance.

[Ianab]

Have to wonder if a Sterling cycle engine wouldn't be more practical as a generator?

You have a wood fire going to produce heat / hot water, and use some of the heat to power a small Sterling engine connected to an alternator / battery etc. You aren't worried so much about the efficiency as the rest of the heat is being used for other things. 

Like Joe says, if you are off grid you want to minimise your electricity usage. The essential things like lighting and electronics can be made fairly low draw. The heating / cooking / hot water are the high load things, so take them out of your electric system. 

[Al_Smith]

Each to his own,I heard of one crazy begger that made a cylinder sleeve for chainsaw :D ;D

guilty as charged  :D

[Magicman]

Scroll down to Ron57's wood burning truck:  LINK

I wish that there was a video.

[pineywoods]

i built a small wood gasifier using 2 old propane tanks. The idea was to use wood gas to run a generator for standby power. Then had one of them "aha moments" why can't we store woodgas or convert it to something that would be long-term storeable. There is a nearby chemical plant that uses natural gas (similar to wood gas) as feed stock to produce several different products some of which are flameable liquids. So ran my idea past an engineer there. Turns out the germans developed such a process during ww2 to produce diesel fuel from coal. Requires pressures above 2500 degrees at temps above 1000 psi in the presence of catalysts. Definitely not suitable as a back-yard project. 

[peakbagger]

Fischer Tropsch process.

[Al_Smith]

I'd imagine about anything in raw crude oil would be in coal, peat, wood .It's just the method of extraction as to  what you might get out of it .Good exercise in the fields  of physics and chemistry .Interesting subject for certain